Single-contact and multiple-contact electrical connector systems are widely used for many household and industrial applications. Typically, such connector systems include a plug and a compatible receptacle, each of which includes one or more electrical contacts which are interconnected when the plug is mated with the receptacle. Plug and receptacle housings or “shells” are provided which position the contacts in alignment with each other, maintain the contacts in secure connection with each other, and protect the electrical contacts from the environment when the connectors are mated. Typically, the housings at least partly overlap when the connectors are mated, with the outer housing being referred to as the “receptacle” and the inner housing being referred to as the “plug.” Often, a latching mechanism is included with the housings so as to avoid inadvertent separation of the plug from the receptacle.
Mid-power connector systems typically must be able to support and protect one or more high current connections and/or a plurality of densely packed connections under conditions that may be environmentally and/or physically challenging. For example, connectors used in solar or wind-power installations are often required to support high currents and to withstand exposure to sun, wind, and rain. Mid-power connectors used in a marine environment such as on a drilling platform or on a yacht may be exposed to prolonged salt spray. Connectors used in industrial environments, such as in food processing plants, may be exposed to periodic impact by pressurized water during cleaning operations.
In some applications, it is desirable for mid-power connectors to be as compact as possible. For example, in solar power installations and in yachts it is often necessary for a plurality of mid-power connectors to be co-located in a limited space, either as separate pairs of connectors or as a plurality of closely-spaced connectors attached to a panel. In addition, it is often desirable for mid-power connectors to be easily and quickly connected and disconnected. And in some applications, mid-power connectors are required by applicable codes to be releasable only through use of a tool.
FIG. 1A is a perspective view of a prior art mid-power connector plug 100 which accepts a plurality of male or female pins 102 (a male pin 102 is illustrated) that can be installed in a male connector body 104.” The plug 100 includes a housing 106 in which are formed three spiral grooves 108. The matching receptacle 110 is illustrated in FIG. 1B. A female pin 112, representative of a plurality of male and/or female pins, is illustrated as being inserted into the receptacle connector body 114. The receptacle housing 116 is surrounded by a large collar 118 which can rotate freely about the housing 116. The collar 118 has three latching pins 120 inserted at equally spaced locations about its circumference, which extend inward and mate with the three spiral slots 108 of the plug housing, so that rotation of the collar 118 pulls the plug and receptacle housings together and locks them into place. In addition, the plug housing 106 includes “wear pins” 122 that retain the collar 118 in its locked position and inhibit it from inadvertently rotating and releasing if the plug and receptacle are pulled in opposite directions.
While the prior art connector of FIGS. 1A and 1B are operable, they have several deficiencies. First, the latching mechanism provided by the plug housing slots 108 and the receptacle housing and collar 118 is very bulky. This is especially true if they are manufactured out of plastic, since plastic parts in this design must be very thick to provided sufficient durability and performance. The bulk can be reduced by making the housings 106, 116 and collar 118 from a metal, such as stainless steel, but in that case the mechanism is very expensive, due to the number and complexity of the metal parts required 106, 116, 118, 120, 122.
In addition, under typical conditions of use, installation and release of the connectors can require application of a significant amount of twisting force to the rotatable collar 118, possibly while holding the plug stationary with the other hand. Depending on the physical strength of the user, this can lead to strains or other injuries. And under conditions where the connectors are packed closely together or are otherwise located in cramped spaces, it can be difficult for a user to surround the collar 118 with his or her fingers and apply the required torque, especially if it is also necessary to hold the plug housing 106 with the other hand.
What is needed, therefore, is a latching mechanism for a mid-power connector system that is comfortable, easy, and safe to engage and release, even under cramped conditions, highly compact, durable, and inexpensive to manufacture.